When the parts are chilled with shell freezing the thermal properties of the frozen layer change, and a large cooling quantity is stored in the frozen shell. For the same equalized temperature the chilling time is therefore shorter than without shell freezing. Shell freezing is freezing of the outer layer of the carcass part, e. g. the outermost 1 to 5 mm of the carcass part. Meat freezes at temperatures of between-1.8 and -6 °C.